Automatic signaling device for telephone-exchanges



(No Model.)

0. E. SORIBNER & F. R. MGBERTY.

AUTOMATIC SIGNALING DEVICE FOR TELEPHONE EXCHANGES.

A No. 574,280.

Paten ted De0. 29, 1896.

UTHQ, wasumnwm n cy UNTTED STATES PATENT OFFIC CHARLES E. SORIBNER, OF CHICAGO, AND FRANK R. MCBERTY, OF DOIV- NERS GROVE, ILLINOIS, ASSIGNORS TO THE WESTERN ELECTRIC COM- PANY, OF CHICAGO, ILLINOIS.

AUTOMATIC SIGNALING DEVICE FOR TELEPHONE-EXCHANGES.

SPECIFICATION forming part of Letters Patent No. 574,280, dated December 29, 1896. Application filed November 27,1894. Serial No. 530.139. (No model.)

T0 at whom, it may concern:

Be it known that we, CHARLES E. Scans- NER, residing at Chicago, in the county of Cook, and FRANK R. MOBERTY, residing at Downers Grove, in the county of Du Page,

State of Illinois, citizens of the United States,

have invented a certain new and useful Improvement in Automatic Signaling Devices for Telephone-Exchanges, (Case No. 367,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

Our invention relates to the mechanism of telephone-exchange systems, its object being to provide means for automatically transmitting signals from the central station to the substations of the system in the act of estab lishing connection with the lines at the central station.

In the telephone exchange organization which is now generally in use each telephoneline from a substation to the central station terminates in a spring-jack or connectionsocket at the central station and is provided with a bell for signaling purposes at the substation. The attendant at the switchboard is furnished with a number of plugs adapted for insertion into the connection-sockets to establish electrical connection with the line and with an equalnumber of switch-keys, one in circuit with each plug, for looping a gener ator of signaling-current suitable for the operation of the bell into circuit with the plug. After the completion of a connection with a line called for the operator has been required to manipulate this ringing-key in order to signal the subscriber at the substation. It is the object of our present invention to dispensewith these manually-operated switchkeys and to provide mechanism for performing the same function automatically upon the completion of connection with the line. To this end we connect a source of continuous current permanently with the plug-circuit, so that a continuous flow of current is set up in the line-circuit after connection therewith, and we provide an electromagnetic signaling instrument, as, for example, a bell, at the substation, togetherwith arelay or circuitbreaker, which is adapted to interrupt the circuit periodically for a short time and then to come to rest, leaving the circuit in its normal condition. This relay is of special construction and constitutes a feature of our in vention. It comprises an electroinagnet a Vibrating weighted tongue or pendulum carried by the armature of the electromaguet, and switch-contacts controlled by the tongue or pendulum. When the magnet is excited, its armature is brought quickly to its pole,whereby the weighted tongue is set into vibration and the current through the bell is periodically closed or interrupted. The vibration of the weighted tongue soon ceases, however-,and the switch-contacts controlled by the tongue return to their normal position.

It will be obvious from this general description of the mechanism of our invention that when a connection is made with a line at the central office the relay at the substation of that line will be excited and will cause the substation-bell to ring during a short time, the length of time being dependent on the adj ustinent of the relay.

We have illustrated our invention in the accompanying drawings and will proceed to describe it in detail with reference thereto.

Figure l of the drawings represents diagrammatically an exchange system comprising a central station and two substations connected with it. The system is organized to receive current for operating the microphones and bells from a common source of supply at the central station-a battery, which is connected with the plug-circuits employed for uniting telephon e-lin es. The substations are furnished with our apparatus for permitting the momentary ringing of the signaling-bell, alternative forms of the invention being shown at the different substations. Fig. 2 is a View of the relay for controlling the operation of the bell.

Referring to Fig. l, A and B designate the substations, and C the central station.

telephone-lines 1 2 and 3 4 from the substation terminate in spring-jacks or connectionsockets d and cl in the switchboard at the central station, and are connected with line annunciators or signals 6 and 6. Each The 9 spring-jack comprises two eontact-piecesa thimble fand a springf, the latter resting normally upon an anvil f The connection of the line with the corresponding lin e-signal is through the spring f and its anvilf A battery 9, which may, if desired, be common to the diii'erent annuneiators of the exchange, is connected in the circuit with the signal.

The switchboard is equipped with the usual connecting-plugs h and 7t, adapted to fit the spring-jacks, and with appropriate circuit connections. The plug has two contactpiecesnamely,a spherical tip i and a tubular sleeve z"-which correspond in position with the contact-pieces of the sprin g-jack. When the plugis inserted in the spring-jack, the tip i registers with spring f of the spring-jack, lifting the spring from its anvil and thus interrupting the connection between the line and the signal, while the sleeve 1" makes contact with the thimble f. The tips dot the two plugs of a pair are connected together through a conduetor5, and the sleeves i through a conductor 6. In a branch or bridge wire 7 between the conductors 5 and 6 of the plugcircuit a battery 76 is included, a retardationcoil Z being placed in the circuit at each side of the battery in order to prevent cross-talk between the different plug-circuits which may be connected in common with this battery. The operator is provided with the usual telephone set an and with a key n, controlling its connection with the conductors of the plugcircuit. Two clearing-out signals 0 and 0 are included in the conductor 5, one at each side of the connection from the battery to that conductor.

At the substation A a telephone CL and a microphone a, asignal-bell a and a relay (0 are located, together with an automatic telephone-switch a, which acts to switch the telephone appliances into connection with the line when the telephone is removed from the switch-hook.

The relay a may be best described in connection with Fig. 2. This instrument comprises, essentially, a magnet p,its armature p, a tongue 12, carried by the armature, and switch-contactsp p ,controlled by the tongue. The armature is carried by a pivoted lever 12 and is normally retracted from the magnet by a spring 11. The tongue p is preferably of steel and is so thin that it may be thrown into vibration by a movement of the armature. It carries at its upper extremity a weight 1) to increase its inertia and to reduce its period of vibration. The contact f is mounted upon the extremity of a light spring 11 which presses the contact-point against its anvil 19 The spring p carries also a projection or stud The spring 19 is so located that when the armature p is drawn up to its magnet and the tongue 13 is not in vibration the stud or projection 1) does not touch the tongue, but when the tongue is vibrating with sufiioient amplitude it will strike the stud p", arid will thus lift the contact 0 from its anvil p at each oscillation, interrupting their electrical connection. Hence when magnet 12 is excited its armature will be quickly drawn up to rest against its pole, the momentum of weight 1f throwing the tongue into vibration. In each oscillation in one direction the tongue will separate the contacts 11 [1' until the vibration has practically ceased and the tongue remains stationary.

At station A of Fig. 1 the relay a is connected permanently between the conductors 1. and 2 of the line-circuit. The bell a is also connected in a branch between these conductors, its circuit including, however, the contact-points 11 of the relay. At station B a different arrangement of circuits is shown, the contact-poin ts p p being disposed to close the circuit through the bell when the tongue 13 comes to bear upon the stud 7). The hell (1 at station B is thus normally not in connection with the line, but receives a pulsatory current from the line during the operation of relay 11 The system herein shown is arranged for the automatic transmission of all the necessary signals between the substations and the central station. The circuit-controller a" and bell a at station A and the circuit-controller I) at station 13 are constructed with so high resistance that the currents from battery g through the signals 6 and c are insufticient to operate the signals, while at the same time the relays and bell receive insufficient current to actuate them. \Vhen a telephone is removed from a switch-hook at the substation, however, as, for example, at substation A, the battery g finds circuit through the comparatively low resistance path, including the telephone ctand microphone a, and the signal (2 is caused to display its indicator. The attendant at the switchboard perceiving this signal inserts plug 71 in spring-jack (I, thus continuing the line-circuit l 2 to the corresponding conductors 5 (3 of the plug-circuit.

By the insertion of plug 7b in the spring-jack d the circuit through signal 0 and battery g is interrupted and the indicator of the signal returns to its normal concealed position. At the same time, however, a circuit is created for battery 7a through the clearing-out signal 0 in the plug-circuit to the line conductors, and thence through the telephone branch at the substation, and signal 0 is operated. Having learned from subscriber at station A with what line connection is desired, as, for example, with station 13, the operator inserts plug h of the pair into spring-jack (l', which forms the terminal of that line. The circuit of battery is thus completed to the conductors 3 l of line to station B and the current finds circuit at the substation through relay Zr. The armature of the relay is drawn up and its tongue 11 is thrown into vibration, closing a circuit from lines 3 4 through hell b periodically, and thus ringing the signal-bell.

When the subscriber at station 13 has removed his telephone from. the switch-hook,

ICC

the circuits are in condition to permit of communication between the two subscribers. A constant current is set up in both line-circuits 1 2 and 3 4 through their respective telephones a-nd microphones a a and b b, the two signals and 0 being operated by the current through them. The operation of microphone to produces undulations in the current in the line-circuit 1 2, which undulations, being prevented from transmission through the bridgewire 7 by the presence of the retardation-coils Z in that circuit, are transferred to line-circuit 3 4 and affect the telephone 1) connected therewith.

When either subscriber replaces his telephone upon the switch -hook, the current through the corresponding clearing-out signal 0 or 0 is interrupted, and the signal, by'returning to its normal position, notifies the operator of this act of the subscriber. When both telephones have been replaced on their switchhooks, the operator may assume that conversation between the subscribers is completed and may withdraw plugs h and h from the spring-jacks.

Having thus described our invention, we claim as new and desire to secure by Letters Patent- 1. In combination, an electromagnet in an electric circuit together with a source of current and means for closing the circuit, a tongue adapted to be thrown into vibration when the said magnet attracts its armature, switch-contacts actuated by the vibrating tongue to open or close a subsidiary branch or circuit, and an electric bell in the subsidiary branch or circuit, substantially as described.

2. The combination with a telephone-line, of a bell at the substation, a source of current in circuit therewith, and mechanism adapted to periodically break and close the circuit through the bell a limited number of times while the magnet remains continuously excited, substantially as described.

3. The combination with a telephone-line, of a bell at the substation, and a source of current in circuit therewith, a circuit-controller or relay adapted to periodically break and close the circuit of the bell a limited number of times while the magnet remains continuously excited, and means for actuating the circuit-controller, substantially as described.

4. The combination with a telephone-line, of a bell at the substation, an electromagnetic relay or circuit-controller thereat adapted to periodically break and close the circuit of a source of current through the bell a limited number of times, and means for closing current through the magnet of the relay when connection is made with the line at the central station, substantially as described.

5. The combination with a telephone-line, of a bell at the substation thereof, an electromagnetic relay or circuit-controller adapted to periodically break and close the circuit of a source of current through the bell a limited number of times, the magnet of the relay being connected with the telephone-line at the substation, and means forclosing a source of current to the line when connection is made therewith, to operate the relay, substantially as described.

6. The combination with a tongue or pendulum adapted to vibrate, of an electromagnet adapted when excited to set the tongue or pendulum into vibration, switch-contacts controlled by the tongue or pendulum, and an electric bell in circuit with the switch-coutacts, substantially as described.

7. The combination with a telephone-line, of a relay comprising a magnet, a flexible weighted tongue carried by the armature thereof, and switch-contacts adapted to be actuated by the tongue, when the latter is thrown into vibration by the movement of the armature, a bell in a circuit controlled by said switch-contacts, and means for closing a source of electric current to the line when connection is made therewith at the central station, the magnet of the relay being connected with the line to receive current therefrom, substantially as described.

In witness whereof we hereunto subscribe our names this 8th day of November, A. D. 1894.'

CHARLES E. SCRIBNER. FRANK R. MOBERTY.

Witnesses ELLA EDLER, LUcILE RUssELL. 

